Answer:
the pressure at B is 527psf
Explanation:
Angular velocity, ω = v / r
ω = 20 /1.5
= 13.333 rad/s
Flow equation from point A to B
![P_A+rz_A-\frac{1}{2} Pr_A^2w^2=P_B+rz_B-\frac{1}{2} pr^2_Bw^2\\\\P_B = P_A + r(z_A-z_B)+\frac{1}{2} pw^2[(r_B^2)-(r_A)^2]\\\\P_B = [25 +(0.8+62.4)(0-1)+\frac{1}{2}(0.8\times1.94)\times(13.333)^2[2.5^2-1.5^2] ]\\\\P_B = 25 - 49.92+551.79\\\\P_B = 526.87psf\\\approx527psf](https://tex.z-dn.net/?f=P_A%2Brz_A-%5Cfrac%7B1%7D%7B2%7D%20Pr_A%5E2w%5E2%3DP_B%2Brz_B-%5Cfrac%7B1%7D%7B2%7D%20pr%5E2_Bw%5E2%5C%5C%5C%5CP_B%20%3D%20P_A%20%2B%20r%28z_A-z_B%29%2B%5Cfrac%7B1%7D%7B2%7D%20pw%5E2%5B%28r_B%5E2%29-%28r_A%29%5E2%5D%5C%5C%5C%5CP_B%20%3D%20%5B25%20%2B%280.8%2B62.4%29%280-1%29%2B%5Cfrac%7B1%7D%7B2%7D%280.8%5Ctimes1.94%29%5Ctimes%2813.333%29%5E2%5B2.5%5E2-1.5%5E2%5D%20%20%5D%5C%5C%5C%5CP_B%20%3D%2025%20-%2049.92%2B551.79%5C%5C%5C%5CP_B%20%3D%20526.87psf%5C%5C%5Capprox527psf)
the pressure at B is 527psf
The energy used by the light bulb in half an hour is 180000 J and the amount of thermal energy generated is 158400 J.
What is Energy?
Energy is the ability or the capacity to do work.
To calculate the energy of the light bulb we use the formula below
Formula:
- E = Pt.......... Equation 1
Where:
- E = Energy used by the bulb in a half-hour
- P = Power of the bulb
- t = Time
Given:
- P = 100 W
- t = 1/2 hour = 30 minutes = (30×60) = 1800 seconds
Substitute these values into equation 1
- E = (100×1800)
- E = 180000 J
- If the light converts 12% of electric energy to light energy, then 88% of the energy is used to generate thermal energy
Therefore,
- Thermal energy = (180000×88/100) = 158400 J
Hence, the energy used by the light bulb in half an hour is 180000 J and the amount of thermal energy generated is 158400 J.
Learn more about energy here: brainly.com/question/21927255
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Answer:
a shiny smooth leaf
Explanation:
A shiny smooth leaf will cause specular reflection. Other choices will cause diffused reflection from the surface.
A specular reflection is similar to how a mirror or smooth surface reflects. The incident light is given off as a single ordered reflection from the surface of a body.
For this to occur, the surface incident must be smooth and without rough patterns on it.
A path way with rough rocks, small patch of soil and rough logs will give off diffused reflection
